Method of tunnel construction.



l. F. O'ROURKI'.4 METHOD 0F TUNNEL CONSTRUCTION.V

APPLICATION mm nov/.11. 1995.

y 1,235,233. IMenwa Jul-y 31,1917.

4 suns-sneer 1.

1. F. OHQURKE. METHOD or TUNNEL consmuclow.

APPLICATION FILED NOV. I1. I9i5.

Patented July 31, 1917.

.Ww-Cli! I 1. F.`o'11oum .A

METHOD 0F TUNNEL CONSTRUCTION.

APPLICATION FIL'ED NOV. I?. T915. n

Patented July 31, 1917.

l. F. OROURKE. METHOD 0F TUNNEL CONSTRUCTION.

APPLICATION msn Nov. l1. |915.

Patented July 3l; 1917.'

4 SHEETS--SHEET 4.k

UNITED STATES lPATENT oEEIcE.

JOHN F. OROURKE, F NEW YORK,'N. Y.

METHOD `or TUNNEL CONSTRUCTION.

"4 To all whom'zt may concern: f

struction, of which the following is a specification. n n

In constructing tunnels havmg llnmgs 1t frequently happens that the ground ,overA and at the sides of the tunnel borlng settles for falls into thel space between the lining and the wall of the boring, therebypermitting the settling'of the ground above the tunnel. Where tunnels are constructed beneath streets and roads, and beneath or adjacent to y y and buildings or subsurface structures, such settlementis liable to endanger or destroy the pavements of the roadways and sidewalks the tunnel. Also, in constructin tunnels under rivers, bays and the like, an particularly where, the tunnel boring passes through lighter soils, such as quicksand or t mud, or where the level of the tunnel closel approaches the bed of the water, or even 1s f A required to be bored at some places throu h y so1 the bed of the water, where revetted blan ets of clay and rock yon the bottom havey been placed, it is of great advantage to prevent the settlement of the adjacent mud or the like-into the space surrounding the tun-` nel, so that such material will not be disturbed or unduly distorted from its natural condition.` Further, when compressed air is used,` the usual method of groutlng this space fails to -prevent long air `passages backward alon the tunnel' from connecting with upwa assages to the surface-which in turn grow into blowouts.

The object of my invention is to facilitateand render less dangerous the operations involved in shield tunneling by compactly filling with' solid material the space formed between the tunnel lining and the wall of the tunnel boring, such as the space excavated g for the shield that is Vnot filled by the tunll5() nel lining, such solid material servingto prevent the earth, rock, mud and the llke over or around the tunnel lining from seb in]ure or destroy the structures above A and below the surface upon or adjacent to tling or falling` into such space, whereby to preserve substantially undisturbed the earth, rock and the like` adjacent to the tunnel boring. p

A further object of my invention is to reduce or retard, by means of the aforesaid filling of solid material, the escape of compressed air (that may beused during the constructionof the tunnel) from a tunnel shield, whereby a minimum amount of compressed air may be required, and the air pressure required may alsobel greatly reduced,`since the filling of the aforesaid space with solid material serves to oppose the rapid diffusion of the compressed a1r escaping from the tail of the shield without enough resistance otherwise to holdthe compressed air, and also to keep the pressure below that required by the immersion if directly felt.

' In carrying out my invention I lilow into 'the space between the wall ofthe tunnel boring and the `tunnel lining, and in-some instances in a space outside 'of' a shield, a

strong current of highly compressed air-car` rying gravel, sandor othersolid filling matl ter with it, to provide in such space a filling of 'solid material compacted between said Specication of Letters Patent.` -Patented July 31, 1917. i Application led November'17,1915. Serial No. 61,597.

wall and lining or shield, to prevent .settlenient of Ythe surrounding rock, earth etc., in4

such space and to cut off the escaping air ,from the tunnel at the point filled when compressed air is used in making the excavation. As tunnel'linlngs are frequently Amadeof rings secured together at their edges, which rings. usually comprise sectionsl of iron, concrete or the like, I preferably convey the gravel, sand or other like solid material into ,the space surrounding such with such force as to compact it solidly,\j ust after the ring has been cleared by the shield, to anticipate settlement of the ground before such settlement begins, although it may be that 'some loose earth or rock may settle in the space 4surrounding the ring before the sa'nd, gravel or the like is compacted in such space, in which event the sand, gravel or the like will be forced into the space left by such falling loose earth or rock. Where a tunnel is constructed bv the use of a shield, the rings of the tunnel lining are usually erectedwithin the tail of tluI shield, and

' when the shield is pushed forward, Step by step, the space left behind the tail of the shield between the adjacentring or rings and `pressing of solid matter around the tunnel the surrounding wall of the tunnel boring, is forcibly charged with the solid material,

before vreferred to. Preferably, such solid material will be charged in sald' space during the time that the shield'is bein pushed forwardly in the tunnel boring, an after it has stopped, until the space is filled, so that the space around the tunnel lining will be compactly filled with solid matter outside of each rin successively as the shield is moved forward y. The solid material may be filled Vin the space around the rings by blowing the material through holes in the sections of the rings, or by blowing1 the solid material. 11nder pressure throng openingsprovided in thevoutside wall or tail of the sh1eld, where by such material may bev blown into` the space behind t'he shield as fast as thelatter. A

is movedforward. Hence, it will be understood that my improved method may be utilized in either of the manners stated, acoord- `ing to the,` circumstances of the case, as occaslon may require. Since compressed airis frequently used within 'shleld-driven ,tunnels, lsuch compressed air-usuallyy finds its way, out 'of thetunnel boring through the space betweenthe shield and the tunne .rings erected therein, and becomesdissipated or diffused through the surrounding ground, usually along well maintained air assages between the lining and the'ground which connect to openings leading to the top of the `ground. Greaterquantities of compressed air at higher pressures than desirable must be used, withiconsequently greater dangers' from its` use under-the high pressures, to avoid which is one of the objects of this invention. By reason of the packing or com rings at or adjacent tothe tail offtheshield, as described, the compressed vair used with, in the tunnel lining and shield is` checked by such solid matteradjacent to the tail of the shield from going farther along the line of the tunnel than near to the point of its first escape. By this means a'mlmmumamount of compressed air may be usedy within the shield and tunnellining, and, furthermore,

the`--pressurewhich otherwise would 'be ref Aquired may be reduced because the escape or rapid diil'usion of air is retarded, thereby rendering such work under air pressure more ..safe, and reducing other damages aswell,

"that are caused by its excessive use. r My invention further comprises novel detailsof improvement and -combinations of parts that will be more fully hereinafter set` forth and then pointed out in the claims.

' r Reference is to be had tothe accompany-v ing drawings forming part hereof, wherein,

Figure 1 is a vertical-sectional lviewof a portion of atunnel and shield illustrating Fig. 2;'-

my improvements, the ltunnel lining being indicated as comprising metallic rings;

'Fig. l is an enlarged detail of part of Fig. 2 is an enlarged transverse detail section of part of the tunnel lining of Fig. 1; Fig. 3 is a cross section von the line 3, 3, in

Fig. 4 is a similar view on the line 4, 4, in

1g. 5 1s an enlarged detail of part of Fig.

2; illustrating the nozzle in position;

Fig. `6vis an enlarged sectional detail of part of the nozzle;

- Fig. .6 is a view at right angles to Fig. 6;

Fig. 7 ,is a. detail of a lug; Fig. 8 is an enlarged) sectional detail of sliir ailid gravel controlling devices shown in 1g.`;. l Fi 9fis a side elevation, partly in section,v of a portion of a tunnel and Ashield illustrating the rings vformed of concrete blocksfand illustrating a modification of the shield; f

Fig. 10 is an enlarged detail section of Fig. 9;-

f Fig; 11` is an enlarged detail section of one of the ring sections of Fig. 9, illustratin 1 the nozzle in position;

ig. 12 is a transverse view partly in section -of the tunnel illustrated in Fig. 9;

Fig. 13 is an enlarged detail section illustrating means for connectin a nozzle with a supply pipe in the shield o Fig. 9;

Fig. I4 is a section on the vline 14, 14, in Fig. 13; f 1

Fig. 15 is a detail side view of parts shown in Fig. 13; A

Fig.'16 is a detail side view of a portion of aI nozzle adaptedto be used in the vshield of Fig. 9; I

Fig. 17 is a section on the line`17, 17, in Fi .16, and

ig. 18 is a sectional detail illustrating the nozzle of Figs. 9, 16and 17 in position at the tail of the shield. A

Similar numerals of reference 'indicate corresponding parts in the several views.

In the accompanying drawin the numeral 1 indicates a boring in t e earth 2 for a tunnel. At 3 is indicated, generally, a shield which may be of any usual or suitable construction, adapted to be used in conflanges of t e sections being secured together by bolts indicated at 7, while in Figs.

9 to 12 the tunnel lining is represented as formed of rings comprlsing concrete-block sections 6 having complemental projections structing tunnels of the class 8 and recesses 9 fitted to ether in a. wellknown manner, such as il ustrated in Letters Patent granted to me Nov. 5, 1912, No.

1,043,348. As illustrated inthe accompanying drawings, and as customar in conerein rel ferredto', the shield is installed in the tun nel boring, and one -or more rings of the tunnel lnin are erected within the tail 3 of the shiel and secured to the previously set rings, the shield'being pushed forwardly through the tunnel boring, step by ste ,by

`means of jacks (L, after the rings are 1n position, in accordance with the esired practice. Between the tail 3 of the shield, and the adjacent ring or rings of thel tunnel lining, is a space 10, and since the ringsl usually rest upon the tail of the shield, the space 10 is wider at the top of the rin s than at the bottom, and is graduated in imensions from the top to the bottom. Into such space, and preferably that indicated `at 11 behind the tail of the shield and between i ,so

the rings and earth 2, I blow solid material, with compressed air, such as gravel, sand and the like, indicated at 12, to` solidly and compactly fill such space around the tunnel lining, to` at once support the tunnel lining and hold backthev surrounding ground. The gravel, sand or the like may be blown into the space l1 through apertures 6a in the ring sections, which. apertures are usually provided in cast iron sections and..

a nozzle at 14 adapted to be connected by any suitable coupling, as 15, with a hose or pipe 16, communicating with sources of 'compressed air, gravel, sand or the like. yIn

the example illustrated I have shown a tank -or the like 17, located within the tunnel, provided with an outlet 18 at its bottom for i solid matter, such as gravelVsand or the like 12. An outlet fitting 20 connected with tank outlet 18 is shown vprovided with a cock or valve 2l to control the flow of solid matter from 'tank 17.l Said fitting is connected with hose or pipe 16, said parts be ing shown connected with a T-fitting 22 whichin turn is connected with an air supf ply pipe 23, provided with a suitable valve 24. Pipe 23 may be connected with an air `supply pipe line 25 utilized in the tunnel for supplying compressed air in a wellknown manner. Tank 17 is shown provided with a lid or cover 17 adapted to permit the tank to be charged with gravel, sand or aced 4threads in the apertures -61 the like, which llid or cover is adaptedV to` be closed vby air pressure within the tank. While air pressure from ipe 23 may enter the tank through the fitting 20 to pass, u

through' the solid matter in thetank, I pre erably connect an air supply directlyv with y the upper `portion of thie tank by means of by-pass pipe 26, shown connected with 'the air pipe line and provided with a. valve 27, whereby the pressure in the tank may be lkept uniform, and the air supply at the top of the tank causes quick closing of the lid or cover. When the tank has been charged with the solid material to be used, a suitable quantity of water may be placed in the tank as `through pipe 19, before the air pressure is admitted to the tank. Whenever the ground contains sufficient waterto mix with and puddle the inserted material water may be omitted from tank 17.

Tank 17 may be carried upon a suitable frame 28 mountedV upon supports 29 within Vthe tunnel, said supports being shown provided with rollers 30 upon which the runners 31 lof said frame are adapted to rest,

Vwhereby the frame'and tank may be moved along in the tunnel as required.

The nozzle 14, may be of any suitable construction having a bore adapted to permit the outflow of gravel, sand or the like into the space surrounding the tunnel lining. y By preference, said nozzle is provided with openings 14 on opposite sides, and said noz l" zle` preferably may be set inthe ring section so that the openings face inthe direction of` the curvature of the ring. Preferably the nozzles are provided with closures 1.4 at their outer ends, which closures have inwardly projectingportions 14 6) opj posln the corresponding openings 14, where y the -gra"el, sand or the like will be directed through openings 14. By preference the side faces 14c of portion 14 of said plug are in concavo form to direct the solid material through openings 14a in a direction around the tunnel ring. When desired .the

nozzle may have one opening 14EE and one i face 14c opposing the same. By preference theend of the nozzle is capped, such as by Ineansof the flange 14*i at the end of plug1 14h to prevent injury to the threads at vthe end of thenozzle which connect the vplug thereto. Nozzle 14 is shown provided with threads at 32 to engagev corresponding whereby the nozzle may Abe securely` fitted to the ringsectio'nsto secure the nozzle iny of the rings,

place and to revent leakage of air from the y connection. here metal sections are used for the tunnel rings the plugs 13 may be removed and the nozzles 14 screwed into the.

openings 6 that are threaded in such sec'-` tion, but where concrete ring sections are used, such as indicated in Figs. 9, 10 and 11, the openings 6 of the sections may be made of suitable dimensions and nuts 33 are embedded in the sections, into which the noz. zles 14 ,may be screwed after the plugs 13 have be'en removed from such nuts. In both instances, it will be understood that the openings 14*I are located beyond the threaded portion 32 of the nozzle, so as to protrude beyond the outer surface of the ring section into the space between the ring and the earth, and the -usually closed outer end of ,the nozzle prevents the impact of theoutiiowing avel, sand or the like under pressure against the opposing wall ofthe tunnell boring, although the nozzle may beused with an open end. It will be understood that one or more tanks 17 may be utilized in the tunnel lining, and lone or more nozzles 14 may -be connected with either tank, and

,in turn connected with the appropriate open- 'ing spacers 34 therebetween (Fig. 14) providing spaces 35 between said walls, in any desired number of which spacesgnozzles or pipes 36 may be placed, and extended from the shield, to direct a blast of gravel, sand*- or the like under air pressure through the tailof the shield into the space surrounding the tunnel rings adjacent to the tail of the,

shield. The inner wall 3b is shown prof vided with openings37 to permit the insertion of the nozzles or pipes into the spaces between the walls of the shield, so that suchy nozzles or pipes may be pushed toward the tail of the shield. The nozzles 36 may have a plug 36b at the end and one or more side openings 36, (Figs. 16-18) to direct,the

gravel, sand or the like circumferentially around the tunnel lining, or the nozzles may be provided with the projecting part 14 shown in Figs. 6 and 6. The nozzles or piIpes may have joints as illustrated at 38 igs. 13 and 18) for coupling different lengths of the same together. After the nozzles or pipes have been placed 'in the spaces between the walls of the shield they may be connected to the meansfor deliver-l ing the compressed air and gravel, sand or the like. Any suitable means may beprovided for connecting pipes 36 withthe supply pipes `or hose 16. vFor this purpose I vhave illustrated a litting 40 adapted to be secured by screws 41 to the inner wall 3" of the tail of the shield and adapted to be operatively united to the adjacent end of the pipe or nozzle 36. The tting 40 is shown providedwith a bore 40,jleading to a side outlet 40", the edges `at 40 of which 10, 13 and 15). After the nozz Lesespa outlet are formed in an angular direction to receive the correspondingly angularly formed edges 36* of nozzle or pipe 36, (Figs.-

e or pipe 36 has been set in place the fitting 40 may be inserted in the corresponding opening in the wall of the shield, so that its edges 40 ywill coact with the redges 36 to make a substantially tight fit whenA the fitting is secured to the shield wall. The coacting edges 40 and 36l serve to keep the nozzle or pipe 36 "from' dis lacement. Pipe 16 may be screwed to tting 40l after or before the latter has been placed in cured by the screws 41,- en more than one 'nozzle or pipe 36 is fitted within the .tail ofthe shield a vi'ltingrl() may be .ap-

plied to each of such-nozzles or pipes and the corresponding pipe l-16 may be connected with one or another tank 17, to be supplied with highly compressed air carrying gravel, sand or lthe like in a manner before described, or in anyother suitable manner.

When the solid material is to be blown or compressed inthe space around the tunnel lining, according to theV arrangements shown in Figs. 1 to 6, one or more plugs 13 may be removed from the corresponding ring sec-- tion or sections, the corresponding nozzle or nozzles 14 inserted with their' outlets projecting beyondthering or rings and facing in the directionfof the curvature of the ring behind the tail section,l and the tank or tanks 17 having been charged with gravel, sand or the like, and vwith zwater, when desired, the corres nding cocks 24 and 27 will be open and substantially simultaneously therewith ,the cock or .cocks 21 will be opened, whereby the compressed air flowing :through tting 2,2,4 to pipel 16 will carry along with 'it the gravel, sand orthe like that flows from tank 17, and such gravel, sand or the' like will be blown from the nozzle or nozzles 14'into'the space surrounding and at the rear of thecorresponding tunnel ring, thereby compacting such material into the space between the tunnel ring and the wall of the tunnel boring.v The operationjust described may be carried out within Athe timeV that :the shield yis being shoved forward, or 'after the shield has been shoved forward, or both, so as to fill the space left behind the tail of the shield as rapidly as possible.

It is not always necessary to introduce waterl lwith. the material, especially where the spaces being filled contain water in suficientA quantities to render the operation successful. l ,.f y V I Where the .form of structure is usedv as illustrated in 9 to 12, the same procedure of blowing the compressed air carry-4 ing the gravel, sand or the like'with it is carried out, and in'such 'case the solid material, being blownA from the tail of the osition and sejacent to the tail of the shield itself.

and thev charging the like may be blown through the openings 6 in the rings andfialso from the tail of the shield simultaneously, if desired. After the s ace around a given ring or rings is c arged in the manner stated, the nozzle or nozz es 14 will be removed and the plugs 13 placed in the corresponding openings 6a, of `the s ace around the tunnel lining will procee ring by ring, after they have been set. The wall of the tunnel boring surrounding the ring will be immediately supported upon the tunnel lining by such compacted solid material before Settlement of the adjacent ground begins, and such filling of such space may be done in such a solid ymanner as to prevent or retard air at the tail of the shield from going farther along the tunnel lining than ad- Where a shield is givena lead7 in a direction different from that of the line of a tunnel, as where the propelling jacks in the bottom, top or sides of the shleld are used separately in such manner as to incline the shield to an upward, downward. or lateral `direction of forward motion, a space or cavit will'be left between some portion of the s ield and the wall of the tunnel boring, due tothe forcing of the shield'sideias wise into the ground away from the direct line, thereby leaving a space on the outside of the shield away from the direction in which it was diverted. In order to fill such space `at the forward portion of the shield with gravel, sand or the like, I provide any desired number of assages, tubes or nozzles 45 in the forwar end of the shield, to

`which one or more pipes 16 from tank 17 ma be attached, by means of a'nozzle 14 if desired and this space is filled as the same is produced `by the lateral motion of the shield. `At 46 the shield is provided with any desired number of openings, to which pipes 16 or their nozzles may be attached,

A to be used for the same purpose yas that described with respect to openings 45, but at the rearward portion of the shield, since an o ning produced by vthe lateral, upward or ownward motion already referred to would extend substantially the entire length of the shield. In some cases where the shield is not given a lead, and is `moved forward directly into the excavation produced at itsforward face, the ground above the face of the shield may fall in for some distance, thereby causing cavity, which may be partly lled from the face of thc shield in the ordinary manner, and any remaining cavity `at the time that the forward motion of the shield reaches the point, as at A, Fig. 1, when the filling of the cavity may be completely perfected byv the solid material forced through ing 45 inthe shiel Any remaining cavity around the shield may be filled by the solid material from the nozzle through onel or l more of the openings 46.

a corresponding open- In case the tunnel is being bored through unstable ground, such as through mud,

quicksand and' the like, it may be desirable to force grout into the ground around the forward portion of the shield, so that such grout may more or less harden and aid in holding'back surrounding soft material of the earth, whereby to prevent undesiredy falling in of the ground before'the space behlnd the Vtail of the shield or outside of the shield can be packed with gravel, sand or the like. Such grout may be forced through the openings 45 or 46 of the shield, or through the nozzles 36 at the tail of the shield, for which purpose any suitable means may be rovided. I have illustrated a tank or chamer 47 mounted upon frame 28 and having a valve-controlled outlet 48 connected with pipe or hose 50, which may be connected by a nozzle 14 or 36 with the desired opening into the tunnel boring. At 51 is a pipe connected with tank 47 through which water `may be supplied to said tank, and at 52 isa valve-controlled pipe leading to said tank, whereby high pressure air may be ,admitted intothe tank. The tank is shown provided with a door 53 adapted to ermit the admission of cement and san ,l which door is adapted to be closed by air pressure within the tank. At 54 is a shaft in tank 47 having paddles or the like 55, which shaft may be rotated in any suitable manner, as by a suitable motor 56 geared thereto.. After the de sired quantity of water, sand and cement have been placed in tank or chamber 47 and shaft 54 has been rotated to mix the materials `as desired, compressed air may be admitted to the tank through pipe 52 ,to cause the grout to be forced under pressure from the tank into the' space surrounding the tunnel lining or the shield, as the case may require. While I have referred to the use of air pressure for forcing solid inaterial into the s ace outside of a tunnel lining or shield, 1t will be understood that other fluid, such as water, under vpressure may be used if desired. i

By means of my improvements I am enabiid to facilitate and render less' danger-a ous the operations involved in tunneling by the use of shields, by reason of the compact filling with some solid material of the space excavated for the shield, which space is necessarily not filled by the tunnel lining. Where a space is left around the tunnel lining behind the shield as it is shoved forward, as has heretofore been the practice, the surrmlnding earth by settling in such space, enables the more readyoutfiow of compressed air from the tunnel du ring progress of the work, thereby requiring theuse Y of an excess amount of compressed air, at higher pressure than is desirable, andsuch settlement of the earth, particularly under streets and -near sub-'surface structures, isY of greatdisadvantage, since the streets must be relaid and'stabilit of adjoining, buildings is endangered.' any advantages are gained by means of my invention, because by compacting solid material inv the space around the tunnel lining, thereby preventing the settlement of the surrounding earth and.

` consequentfallingin of street and roadway surfaces and danger to adjacent structures, I am enabledto utilize a minimum 'amount of compressed air and `considerably reduce thel air 4pressure usually required, sincesuch lling'around the tunnel lining opposes diff -vfusion of -the air along the 'lining-for considerable distances, and' outv through existing, holes, through which such air would often flow .for-a considerable distance. It will alsobeunderstood that whenever ground' further, and very important, advanta e the use of myinvention is t ey settles its capacity for resisting compressed air is greatly reduced, and ina tunnel passing through the lighter soils,'s uch as quick- Sandor mud, such filling of the vvoids about- -the performs the two-fold functionof preventingv the'. mud, quicksand or klother ground from losing its 'own consisten cy,.and,` at the same time, since the compressed air may bei-kept at a lower pressure, what arel called blowouts may be largelyr` avoided.

Inthe event of using. revetted clay blankets overfithe weaker lportions of the. ground' or water bottom, both 'the 4ground and the blanketsl are preserved with alltheir 'origi-j "'-nal vstrength and tightness, both of which' properties would be seriously affected nin the event of settlement of thev ground. A

gained b saving'o `health-and life'which are risked almost always when tunneling at considerable .depths is being done, and

where no meansis provided for keeping the ail-.pressure below that of the water presy sure`,xdue to the depth at which the work is carried on,1since the air pressure mustbe kept high to resist the .outflow of air throughl the'shield toy the Space between the shield and tunnel lining into the surrounding. mud, muck 'and the 'l1ke.y Hence, by filling the space around the tunnellining with h1ghly 'compressed'solid material, 4 as before derevent undue scribed, "thereby serving to escape of air 4from the -shiel and keeping the surrounding mud and muck from disfplacement, thus enabling the use of lighter airpressure. within -the shield Iand tunnel lining, vgivesan advantage of great importance toithe workmen employed and reduces thedan r of v,mud and water flowing into thewoi' enabling the men to work under less pressure. As diiiculties of the last land orcin ysity to wit f space outside t under water -tail of the .along said lining, and blowing acurrent of named character are mostly confined to subaqueous tunneling, the importance of my invention is as great to meet such diili'ulties under bays and rivers as under streets.v

vAs tunnel llinings are frequently constructed of circular rings, or of segments of circles or other curves or planes forming `roofs, sides and bottom of tunnels, which tunnels are not circular in cross section, but in which thelinings arev installed in whole `or in art with the 'use of shields, I have confn the illustrations whereby my inventionmayfbe carried out to the circular formof tunnel. lining having successively .disposed rings constructed in sections, and

itgwill be. understood that my invention is not'limited to use in connection with tunnel .linings of circular rin -like form, as my linvention may--bedarrie out in connection lwith tunnel linings of any desired form.

lHavingvnow described my inventionwhat 1. The method ofvpreventing settlement of earthinto a space outside atunnel consist' in insertin materiallin said space it by impact to an initial denstand pressure of the exterior ground.

2. The method of constructing a shield 4 driven tunnel consisting in projecting and densely packingl'loose solid material into a e tunnel lining to prevent ,settlement of ound into said space.

The met od of constructing a shield drlven tunnel consisting in conveying. gravel or similar material into a vspace outside the tunnel lining and immediately compacting such material in saidfspace to such density as will at once prevent settlement of adacent ground into said .spaces j 4. The method of preventing settlement of the ground into a' spacefaround the lning of a tunnel consisting vin delivering a blast of air carrying material into said space and immediately compacting `by'impact said materialr between the lining and the wall of the excavation to such ,density as will at vonce revent settlement of surrounding gronnl intosaid space.

5. The method of ,constructing tunnels consisting in making altunnel boring4 for 'a shield, erectin va tunnel lining within the 'eld, advancing the shield air carryin Vloosev solid jma f"al :into the space outsi e of the lining vbe d the. tail of the shield against the lining and the Wallv of the boring, compactingfsaid vliiaterial to at once support the surrounding rg'round.

- 6. The method of preventing y-th'e settlement of the earth yinto a space around the lining of a tunnel consisting 'in .delivering a blast of highly compressed air` carrying gravel or similar material and water into said space, immediatelycompacting saidmalterial to approximately the same degre'as that of the surrounding earth to at on the surrounding earth, whereby said sett1e` support the tunnel lining and theground ment is substantially obviated. o above the lining. Y 10 7. The Vmethod of filling a space sur- Signed at New York city, in the `count'. 5 rounding a tunnel liningV consisting in inof New York, and State of New York, thls sorting material in said space and forcing 16th day of November, A. D. 1915. V it by impact to a. density approximating e JOHN F. OROURKE. 

